A Study On Hemodynamics Changes And Collateral Flow In Patients With Middle Cerebral Artery Serious Stenosis Or Ocllusion

Purpose: To investigate the hemodynamic changes and compensation of collateral flow in patients with serious middle cerebral artery(MCA)stenosis or occlusion by the examination of Transcranial Doppler(TCD); Approaching the relationship of collateral flow with the patient's neurologic impairment and providing reliable evidence for the selection of therapy, judgement of prognosis and effective prevention.Objective and Methods: 38 patients with unilateral MCA stenosis or occlusion who received treatment in the second affiliated hospital of NAN CHANG university during February,2006 to January,2007 were selected. 27 of them were male, 11 of them were female, age from 27 to 82 years old, the average age was 54.5±12.9 years. All the patients were identified by the union of TCD and Magnetic Resonance Angiogram(MRA). Patients were scored with NIHSS after hospitalization. Another 50 persons who received healthy examination were selected as the control group. Observing the intracal parameters of hemodynamic changes. Calculating the ratio of bilateral anterior cerebral artery (RVACA) flow velocity and the ratio of the bilateral posterior cerebral artery (RVPCA) flow velocity, compared the data from the healthy controls. Getting the message of hemodynamic changes and compensation of collateral flow after the MCA affedted. Investigating the dependability between RVACA \RVPCA and NIHSS.Results: In patient group,76.3% of the patients has compensative acceleration of the ACA velocity,39.5% of the patients has compensative acceleration of the PCA velocity.The blood velocity ratios of ACA in the patient group (1.49±0.59) was significantly higher than ratios for controls.There was a significant difference compared with the contol group (t=3.618,p<0.01) .The blood velocity ratios of PCA in patient group was 1.03±0.37, There was not statistically significant compared with the contol group (t=1.247,p>0.05),but the blood velocity ratios of 15 patients who has compensative acceleration of the PCA was 1.20±1.16,it has a statistical significance compared with the contol group (t=2.236,p<0.05). There was a inverse correlation negative correlation between the RVACA and the NIHSS in patient group﹙r=-8.10,p<0.01﹚. no dependablity was found between the RVPCA and the NIHSS in patient group,but There was a inverse correlation negative correlation between the RVPCA and the NIHSS in the 15 patients who has compensative acceleration of the PCA velocity﹙r=-7.06,p<0.01﹚.Conclusion: The opening of leptomeningeal anastomoses vessel is the important way of collateral circulation in cases of serious stenosis or occlusion of MCA,the collateral flow between MCA and ACA is dominant. The RVACA/RVPCA can reflect the hemodynamic changes,the state of leptomeningeal anastomoses vessel when the MCA was serious stenosis or occlusion; There was a inverse correlation negative correlation between the RVACA/RVPCA and the NIHSS.